The royal daughter-in-law (favorite daughter) is a nymphomaniac and a good-for-nothing. Because the scumbag caused the original owner to die. The heroine comes in forcefully, transforming little by little from a good-for-nothing to a monster. Pretending to be a pig and eating a tiger, refining weapons, refining elixirs, and taming animals are all her skills.
The male protagonists are jealous of her, pretending to be friendly in front of her, but fighting to the death behind her back. But everyone dotes on the heroine to heaven.